64 FUCACE^.— Halidets. iv. 



handsome shore-plants, and readily known by their articulated, many-celled air- 

 vessels. 



1. Halidets siliquosa, Lyngb., frond compressed, narrow, repeatedly pinnate ; 

 air-vessels compressed, oblong or linear-lanceolate, mucronate, slightly constricted 

 at the septa ; receptacles lanceolate. J. Ag. Sp. Alg., vol. I, p. 236 ; Kiitz, Sp. Alg., 

 p. 604 ; Grev. Alg. Brit. t. 1. ; Harv. Phyc. Brit. t. QQ ; Cystoseira siliquosa, Ag, 

 Syst., p. 287 ; Fucus siliquosus, L. — Turn. Hist. Fuc. t. 159. ; E. Bot. t. 474. 



Habitat. On rocks near low-water mark. Shores of Newfoundland, Herb. 

 Banks (fide Turner), (v. v.) 



Fronds from one to four feet long or more, linear, compressed, two edged, from 

 one to two lines broad, distichous, repeatedly pinnate. Pinnce alternate, the lower 

 ones much lengthened, and either naked below or furnished with a few small 

 branchlets and air-vessels, pinnate or bi-tripinnate above, each successive division 

 becoming narrower. Air-vessels linear-oblong, or lanceolate, supported on slender 

 stalks, and tipped by a slender acumination of various lengths, which some- 

 times ends in a receptacle. The air-vessels are internally divided by transverse 

 membranes into numerous compartments or chambers, and externally marked at 

 each partition by slight constrictions, most visible after the plant has been dried. 

 Receptacles usually forming racemes, which terminate the branches, pedicellate, 

 lanceolate, compressed. Colour., when young a greenish olive ; becoming a rich, 

 glossy brown in age. Substance tough and leathery. 



This plant is very common on the Atlantic shores of Europe, and is said, by 

 Turner, to extend south as far as the Canary Islands. On the same authority we 

 claim it as a native of Ne^vfoundland, but I have never seen any American spe- 

 cimens. The above description is taken from British ones. 



2. Haltoets osmundacea, Harv. frond simply pinnatifid below, with broadly 

 linear, subacute midribbed laciniae ; decompound above, the pinnte and pinnulaa 

 slender, sub-filiform ; air-vessels moniliform, deeply constricted at the septa ; 

 receptacles small, forked, crowning the air vessels. Harv. in Bot. Beechey's Yoy., 

 p. 407. J- Ag. Sp. Alg., vol. 1, p. 237. Kiitz. Sp. Alg., p. 604. Cystoseira 

 osmundacea, Ag. Syst., p. 287. Fucus osmundaceus, Menz. in Turn. Hist. Fuc. t. 105. 

 (Tab. n.) 



Hab. Rocks near low-water mark. At Port Trinidad, on the N. W. coast, 

 Archibald Menzies, Esq. California, Mr. D. Douglas. Monterey, Br. Coidter, 

 (v. s. in Herb. T.C.D.) 



Boot discoid. Frond of unknown length, but probably many feet long when 



